The present invention relates to an electronic traffic light, which is adapted to control vehicular traffic and pedestrian flow through an intersection.
As the traffic load increases, the management of the traffic gains greater importance for traffic engineers and city planners. Traffic lights (traffic signal transmitters) are universally used for the management of traffic. Red, yellow and green lights bear the same meaning throughout the world for all people. The traffic engineers carefully study the traffic flow through intersections, arterial streets and small roads, all in an attempt to make the traffic flow smoothly, without much delay and idling of the engines. Conventional traffic lights are programmed to allow one indicator to only flash for a short period of time before the other illuminates.
Normally, the yellow indicator illuminates only a few seconds before the red indicator illuminates. The motorists and pedestrians do not exactly know the remaining time before the red indicator illuminates. Consequently, the drivers may run a red light because there is no time to respond to this quick change. Sometimes, one vehicle collides with another vehicle in the front which has stopped abruptly when the yellow light started flashing. The resulting accident causes property damage and disrupts the traffic flow through the intersection for a long period of time.
The industry has attempted to solve the problem by offering electronic devices, which work in association with conventional traffic light indicators by counting down the time remaining before the light change. For instance, U.S. Pat. No. 6,268,805 (Simon) discloses a count-down indicator with a digital display that displays (i.e., counts down) the remaining time in seconds until the next signal change occurs. The digital display matches the color of the digits being displayed to that of the illumined light of the signal assembly. A flashing caution light is attached to the digital display and it flashes whenever there is potential that the remaining time can suddenly change in a manner that violates the normal count-down sequence.
While the device of the Simon patent may work satisfactory in many instances, it has certain disadvantages, which may be demonstrated by application to on-demand types of traffic lights that include a normal duty cycle but are able to override the normal duty cycle based on the immediate traffic flow. Such lights are designed to detect the condition of traffic at a particular intersection and decrease the normal cycle of a light indicator that has been programmed by the traffic engineers. For instance if there are thirty seconds of green time remaining and there is no traffic passing through the intersection while cars are waiting at a red light to cross in a perpendicular direction, such on-demand traffic signals will detect this condition and reduce the thirty second normal countdown to only a few seconds before changing. A countdown indicator that is operationally connected to the programmed cycle of the traffic light could mislead a motorist if the light changes without warning, while the countdown indicator still shows in a numerical fashion several seconds of remaining green time.
Therefore, there is room for an improved traffic light device that is programmed to visually and pictorially display the time remaining before the light changes to thereby increase the convenience of the motorists and pedestrians, as well as the traffic safety.